Ok that's just wrong, I have lost faith in the oldtimers that built this.
You have the weight of 1/4 of the roof, 1/4 of the upper floor, 1/4 of the lower floor and 1/2 of the wall all held up by the outside floor joists.
Jacking it up would be the same but longer as these peices will have to bend back to place so lifting may be as slow as 1/8 to 1/4 inch per day.
Once up you would be able to work on the foundation and any repairs along that side.
Then you might consider the same proceedure for the rest of the walls with some other considerations.

Yeah, I ran the numbers after I posted that.
It brings up the question whether anyone makes jacks run by motors through a gear train that runs day and night at the extremely slow speeds you posted.
That way the OP just sets it up and monitors the building once or twice per day, for what might take a month.

And the low power means the whole setup could be run by batteries. I think I'll start hiring illegals to produce this thing.

If you put in good footings to jack on soil settlement is out of the picture.
That side of the building looks like it has never had support. Take the total sag, lets say 4 inches and you devide that by say 100 years and you get some idea how long it took to slump 1/8"
If nails and other fastners didn't do there job it would have fallen down years ago and they will try to do there job when you want to push the other way.
If you had a jack big enough the fear would be that you could over jack the center and if the building resisted you might lift the whole side on one jack, very dangerous.

A few years ago I helped a friend lift the back half of his house to near level. A hand full of 25 ton jacks. 1/8" was easy and the jack would not go 1/4". Another friend showed up and thought he could get more, This jack was cribbed on the basement floor and when the floor broke so did his arm.
Any time you do work like this a good feel and wise fear is in order.

1/8" was easy and the jack would not go 1/4". Another friend showed up and thought he could get more, This jack was cribbed on the basement floor and when the floor broke so did his arm.
Any time you do work like this a good feel and wise fear is in order.

Also a jack that registers the force it is pushing against. A steep increase in force means rethinking the project. Since civil engineers are building from scratch they may not have to worry about this.

I have said before I think in cases like this and as Neal has just pointed out perfection shouldn’t be the goal. I have always felt the key word foremost should be stabilization and then correction. If you take a gob of silly putty and roll it out into a snake and pull rapidly on it, it will snap like a solid piece. If you pull slowly it will stretch and elongate. I know lumber isn’t the same but it has some of the same properties IMO. Going at it slowly over time will allow the fibers a chance to adjust. Just as if 100 years ago that main beam was deflected 6 inches it would have broken but the steady push down over the years allowed it to sag. Windows and doors and everything in the building has moved and I would be looking at it all picking the point I felt enough is enough. And then stabilize the building against a proper footing. If the floors are still to sloped then you get into figuring out how to level them or how to live with them.

Right now I’m working in my old garage that has some of these same issues and I want to support and stabilize the building but I’m only correcting it partway back for fear of really doing some damage.